U.S. patent application number 15/228072 was filed with the patent office on 2018-02-08 for depressible pins clutch pack assembly with separator spring.
The applicant listed for this patent is FORD GLOBAL TECHNOLOGIES, LLC. Invention is credited to Bryant David GRYTZELIUS, Bradley Ronald HEUVER.
Application Number | 20180038427 15/228072 |
Document ID | / |
Family ID | 59752132 |
Filed Date | 2018-02-08 |
United States Patent
Application |
20180038427 |
Kind Code |
A1 |
GRYTZELIUS; Bryant David ;
et al. |
February 8, 2018 |
DEPRESSIBLE PINS CLUTCH PACK ASSEMBLY WITH SEPARATOR SPRING
Abstract
A clutch for an automatic transmission includes a tubular
housing surrounding a clutch pack and having an end for engaging
with a pressure plate. An annular separator spring on the end
provides a biasing force against the pressure plate. A plurality of
depressible pins are disposed in the housing and are located
radially outward from the annular spring for inhibiting radial
movement of the separator spring.
Inventors: |
GRYTZELIUS; Bryant David;
(Canton, MI) ; HEUVER; Bradley Ronald; (South
Lyon, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FORD GLOBAL TECHNOLOGIES, LLC |
Dearborn |
MI |
US |
|
|
Family ID: |
59752132 |
Appl. No.: |
15/228072 |
Filed: |
August 4, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16D 47/04 20130101;
F16D 13/52 20130101; F16D 13/71 20130101; F16D 19/00 20130101; F16D
21/00 20130101 |
International
Class: |
F16D 47/04 20060101
F16D047/04; F16D 21/00 20060101 F16D021/00; F16D 13/52 20060101
F16D013/52 |
Claims
1. A clutch for an automotive transmission, comprising: a tubular
housing surrounding a clutch pack and having an end for engaging
with a pressure plate; an annular separator spring on the end for
providing a biasing force against the pressure plate; and a
plurality of depressible pins disposed in the housing and located
radially outward from the spring for inhibiting radial movement of
the separator spring.
2. The clutch of claim 1, wherein the pins are spring biased toward
the pressure plate.
3. The clutch of claim 1, wherein the housing defines a plurality
of pockets, each pocket receiving one of the pins.
4. The clutch of claim 3, wherein the pins are biased toward the
pressure plate.
5. The clutch of claim 1, wherein the pins are biased to extend
beyond the end of the housing.
6. The clutch of claim 1, wherein the separator spring is annular
in shape.
7. The clutch of claim 1, wherein the pins are located adjacent to
the separator spring.
8. The clutch of claim 1, wherein the plurality of depressible pins
includes exactly three pins.
9. A clutch assembly comprising: a clutch pack stacked along an
axis; a housing radially surrounding the clutch pack; a one-way
clutch axially aligned with the housing and having an end plate
engaging the clutch pack; a separator spring disposed radially
inward from the housing, and between the clutch pack and the
one-way clutch; and a pin between the housing and the one-way
clutch for inhibiting radial movement of the separator spring.
10. The clutch assembly of claim 9, wherein the pins are biased
toward the end plate.
11. The clutch assembly of claim 9, wherein the end plate defines a
depression for receiving the pin.
12. The clutch assembly of claim 9, further comprising two or more
additional pins, wherein the pin and the additional pins are
arranged annularly about the separator spring.
13. The clutch assembly of claim 9, wherein the housing defines a
pocket sized to receive the pin.
14. The clutch assembly of claim 13, further comprising a spring in
the pocket to bias the pin toward the end plate.
15. The clutch assembly of claim 9, wherein the pin extends into
both the housing and the end plate.
16. A method of assembling a clutch assembly for an automotive
transmission, comprising: placing an annular separator ring within
a housing that contains friction plates and radially inward from a
plurality of pins; and placing an end plate of a one-way clutch
onto the housing to contain the separator spring between the
housing and the end plate while compressing the pins into the
housing.
17. The method of claim 16, further comprising, before placing the
end plate onto the housing, placing the plurality of pins within
pockets of the housing located radially outward from the separator
ring.
18. The method of claim 16, wherein the plurality of pins extend
into both the housing and the end plate when the end plate is
placed onto the housing.
19. The method of claim 16, wherein the plurality of pins are
located adjacent to the separator ring to inhibit radial movement
of the separator spring.
Description
TECHNICAL FIELD
[0001] This disclosure relates to a clutch assembly having pins for
inhibiting radial movement of a separator spring.
BACKGROUND
[0002] Many vehicles are used over a wide range of vehicle speeds,
including both forward and reverse movement. Some types of engines,
however, are capable of operating efficiently only within a narrow
range of speeds. Consequently, transmissions capable of efficiently
transmitting power at a variety of speed ratios are frequently
employed. When the vehicle is at low speed, the transmission is
usually operated at a high speed ratio such that it multiplies the
engine torque for improved acceleration. At high vehicle speed,
operating the transmission at a low speed ratio permits an engine
speed associated with quiet, fuel efficient cruising. Typically, a
transmission has a housing mounted to the vehicle structure, an
input shaft driven by an engine crankshaft, and an output shaft
driving the vehicle wheels, often via a differential assembly which
permits the left and right wheel to rotate at slightly different
speeds as the vehicle turns.
[0003] A common type of automatic transmission utilizes a
collection of clutches and brakes. Various subsets of the clutches
and brakes are engaged to establish the various speed ratios. A
common type of clutch utilizes a clutch pack having separator
plates splined to a housing and interleaved with friction plates
splined to a rotating shell. When the separator plates and the
friction plates are forced together, torque may be transmitted
between the housing and the shell. Typically, a separator plate on
one end of the clutch pack, called a reaction plate, is axially
held to the housing. A piston applies axial force to a separator
plate on the opposite end of the clutch pack, called a pressure
plate, compressing the clutch pack. The piston force is generated
by supplying pressurized fluid to a chamber between the housing and
the piston. For a brake, the housing may be integrated into the
transmission case. For a clutch, the housing rotates. As the
pressurized fluid flows from the stationary transmission case to
the rotating housing, it may need to cross one or more interfaces
between components rotating at different speeds. At each interface,
seals direct the flow from an opening in one component into an
opening in the interfacing component.
[0004] In a rear wheel drive vehicle, the engine and transmission
are commonly mounted along a longitudinal axis of the vehicle,
perpendicular to the axis about which the wheels rotate. Power from
a transmission output shaft is conveyed by a driveshaft to a
differential assembly which changes the axis of rotation,
multiplies the torque by a final drive ratio, and permits the
wheels to rotate at slightly different speeds. In a front wheel
drive vehicle, the engine and transmission are commonly mounted
transversely, such that the engine crankshaft rotates about an axis
parallel to the axis about which the wheels rotate. In a front
wheel drive vehicle, it is common to combine the transmission and
the differential into a single unit called a transaxle.
[0005] Several vehicle design trends combine to limit the space
available for a transaxle. A desire to limit the frontal area to
reduce drag and improve styling tends to reduce the engine
compartment width. Switching from engines with the cylinders
arranged in a V pattern to engines with the cylinders inline
increases the length of the engine. At the same time, the number of
distinct transmission ratios has been tending to increase,
increasing the number of parts required in the transmission.
Consequently, transaxles must be designed with some components
radially within other components in order to minimize the total
axial length.
[0006] Some clutches in particular transmissions may have separator
springs. The separator springs bias the clutch pack such that the
free height of the clutch pack attempts to exceed the housing that
holds the clutch pack, biasing the clutch pack against the
housing.
SUMMARY
[0007] In one embodiment, a clutch for an automatic transmission
includes a tubular housing surrounding a clutch pack and having an
end for engaging with a pressure plate. An annular separator spring
on the end provides a biasing force against the pressure plate. A
plurality of depressible pins are disposed in the housing and are
located radially outward from the annular spring for inhibiting
radial movement of the separator spring.
[0008] In another embodiment, a clutch assembly includes a clutch
pack stacked along an axis, a housing radially surrounding the
clutch pack, and a one-way clutch axially aligned with the housing.
The one-way clutch has an end plate engaging the clutch pack. A
separator spring is disposed radially inward from the housing, and
between the clutch pack and the one-way clutch. A pin is between
the housing and the one-way clutch for inhibiting radial movement
of the separator spring.
[0009] In another embodiment, a method of assembling a clutch
assembly for an automotive transmission is provided. The method
includes placing an annular separator ring within a housing that
contains friction plates and radially inward from a plurality of
pins. The method also includes placing an end plate of a one-way
clutch onto the housing to contain the separator spring between the
housing and the end plate while compressing the pins into the
housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic representation of a transmission
gearing arrangement, according to one embodiment.
[0011] FIG. 2 is a partial top perspective view of a clutch having
a clutch pack housed within a housing with a separator spring,
according to one embodiment.
[0012] FIG. 3 is an enlarged portion of FIG. 1 illustrating a
depressible locating pin for containing the separator spring,
according to one embodiment.
[0013] FIG. 4 is a bottom perspective view of a one-way clutch that
is assembled to the clutch of FIG. 1, according to one
embodiment.
[0014] FIG. 5 is an enlarged portion of FIG. 3 illustrating a
depression in the end of the one-way clutch for receiving the
locating pin, according to one embodiment.
DETAILED DESCRIPTION
[0015] Embodiments of the present disclosure are described herein.
It is to be understood, however, that the disclosed embodiments are
merely examples and other embodiments can take various and
alternative forms. The figures are not necessarily to scale; some
features could be exaggerated or minimized to show details of
particular components. Therefore, specific structural and
functional details disclosed herein are not to be interpreted as
limiting, but merely as a representative basis for teaching one
skilled in the art to variously employ the embodiments. As those of
ordinary skill in the art will understand, various features
illustrated and described with reference to any one of the figures
can be combined with features illustrated in one or more other
figures to produce embodiments that are not explicitly illustrated
or described. The combinations of features illustrated provide
representative embodiments for typical applications. Various
combinations and modifications of the features consistent with the
teachings of this disclosure, however, could be desired for
particular applications or implementations.
[0016] A gearing arrangement is a collection of rotating elements
and shift elements configured to impose specified speed
relationships among the rotating elements. Some speed
relationships, called fixed speed relationships, are imposed
regardless of the state of any shift elements. Other speed
relationships, called selective speed relationships, are imposed
only when particular shift elements are fully engaged. A discrete
ratio transmission has a gearing arrangement that selectively
imposes a variety of speed ratios between an input shaft and an
output shaft.
[0017] A group of rotating elements are fixedly coupled to one
another if they are constrained to rotate as a unit in all
operating conditions. Rotating elements can be fixedly coupled by
spline connections, welding, press fitting, machining from a common
solid, or other means. Slight variations in rotational displacement
between fixedly coupled elements can occur such as displacement due
to lash or shaft compliance. In contrast, two rotating elements are
selectively coupled by a shift element when the shift element
constrains them to rotate as a unit whenever it is fully engaged
and they are free to rotate at distinct speeds in at least some
other operating condition. A shift element that holds a rotating
element against rotation by selectively connecting it to the
housing is called a brake. A shift element that selectively couples
two or more rotating elements to one another is called a clutch.
Shift elements may be actively controlled devices such as
hydraulically or electrically actuated clutches or brakes or may be
passive devices such as one way clutches or brakes.
[0018] A transmission gearing arrangement is illustrated
schematically in FIG. 1. Input shaft 10 is driven by an internal
combustion engine, potentially via a launch device such as a torque
converter. Output 12 drives the vehicle wheels, potentially via
gearing and a differential. The various components of the gearing
arrangement are supported within a transmission case 14 that is
fixed to vehicle structure. The transmission utilizes four simple
planetary gear sets 20, 30, 40, and 50. A planet carrier 22 rotates
about a central axis and supports a set of planet gears 24 such
that the planet gears rotate with respect to the planet carrier.
External gear teeth on the planet gears 24 mesh with external gear
teeth on a sun gear 26 and with internal gear teeth on a ring gear
28. Sun gear 26 and ring gear 28 are supported to rotate about the
same axis as the carrier. Gear sets 30, 40, and 50 are similarly
structured.
[0019] Sun gear 46 is fixedly coupled to input shaft 10. Ring gear
38 and carrier 52 are fixedly coupled to output 12. Carrier 22 is
fixedly coupled to sun gear 36. Ring gear 28, carrier 42, and ring
gear 58 are mutually fixedly coupled. Carrier 32 is fixedly coupled
to ring gear 48. Clutch 62 selectively couples ring gear 28 to
input shaft. Sun gear 26 is selectively coupled to input shaft 10
by clutch 60 and selectively held against rotation by brake 64.
Brake 66 selectively holds sun gear 56 against rotation. Brake 68
selectively holds carrier 22 and sun gear 36 against rotation.
Carrier 32 and ring gear 48 are selectively held against rotation
by brake 70 and passively held against rotation in one direction by
one way brake 72.
[0020] As shown in Table 1, engaging the shift elements in
combinations of two establishes eight forward speed ratios and one
reverse speed ratio between input shaft 10 and output 12. An X
indicates that the shift element is required to establish the speed
ratio.
TABLE-US-00001 TABLE 1 60 62 64 66 68 70/72 Ratio Step Rev X X
-3.79 89% 1.sup.st X X 4.26 2.sup.nd X X 2.73 1.56 3.sup.rd X X
2.19 1.25 4.sup.th X X 1.71 1.28 5.sup.th X X 1.33 1.29 6.sup.th X
X 1.00 1.33 7.sup.th X X 0.85 1.18 8.sup.th X X 0.69 1.23
[0021] The transmission may be located adjacent to, or coupled
with, a one-way clutch as part of the transaxle. One example of the
one-way clutch is illustrated in FIGS. 4-5, described below. The
end plate of the one-way clutch may act as a pressure plate for one
of the clutches in the transmission. As part of a clutch assembly,
a separator spring may be provided between one of the clutches of
the transmission and the one-way clutch. The separator spring is an
annular spring that biases the clutch pack while also providing
resistance between the clutch and the one-way clutch. Assembly of
the one-way clutch to the clutch pack sandwiches the separator
spring therebetween. If the separator spring becomes dislodged or
out of proper alignment, replacement or repair of the spring might
require a disassembly of the clutch assembly.
[0022] According to various embodiments of this disclosure, a
plurality of pins are provided radially outboard of the separator
spring. The pins locate the separator spring, and also maintain
proper alignment of the spring by inhibiting outwardly movement of
the separator spring.
[0023] FIG. 2 illustrates a clutch 100. The clutch 100 can be any
of the clutches or brakes 60, 62, 64, 66, 68, 70 described above.
The clutch 100 may also be another clutch outside of the
transmission housing that connects the transmission to a one-way
clutch as part of a transaxle assembly. Any and all references to
the clutch 100 with the separator spring should be understood as
being any of these clutches or an additional clutch not shown in
FIG. 1. In one embodiment, the clutch 100 is a clutch that couples
to a one-way clutch (FIGS. 4-5) as part of the transaxle to deliver
torque to the differential, in which the one-way clutch acts as the
pressure plate for the clutch 100.
[0024] The clutch 100 includes an outer housing 102. The housing
102 contains a clutch pack 104 having a plurality of clutch plates
106 that are selectively compressible to engage and disengage the
clutch 100. Once such clutch plate is a friction plate 108 at an
end of the clutch 100. The clutch plates are annular about a common
central axis.
[0025] A separator spring 110 is also provided. The separator
spring 110 is also annular in shape, and shares a central axis that
is common to that of the clutch plates. An annular groove 112 may
be provided in the housing 102 to fit the annular separator spring
110. Alternatively, the end of the housing 102 may be a flat
surface. The separator spring 110 is biased to cause the free
height of the clutch pack 104 to be larger than the housing that
holds the clutch pack 104. The separator spring 110 acts to open up
the clutch pack 104 in its free state, causing the top friction
plate 108 and separator spring 110 to rise above the end surface of
the housing 102. This is shown in FIG. 1 in which waves or
undulations 116 are seen in the separator spring 110.
[0026] A plurality of pins 120 are located about the outer diameter
of the separator spring 110, radially outward from the separator
spring 110 with respect to the central axis. The pins 120 help an
individual locate the separator spring 110 into proper alignment
during assembly. The pins 120 also retain the separator spring 110
in its proper alignment, inhibiting the separator spring 110 from
shifting or moving radially outward, which would otherwise require
repair.
[0027] In an embodiment, each pin 120 is a cylindrical member. The
pins 120 can also be hollow for reduction of weight. The housing
102 may include a plurality of pockets or apertures defined therein
that are each sized and positioned to receive one of the pins 120.
Contained within each pocket may be a spring to bias the pin 120
outward from the pocket, e.g., in the direction of the one-way
clutch or pressure plate. In this fashion, the pins 120 are each
depressible within their respective pocket in the housing.
[0028] The embodiment of FIG. 2 shows three pins 120 arranged
equidistant from one another about the separator spring 110.
Utilizing exactly three pins 120 is, in certain embodiments,
beneficial for properly inhibiting radial movement of the separator
spring 110 without an unnecessarily numerous number of pins. In
other embodiments, more or less than three pins 120 are
utilized.
[0029] The clutch 100 may be assembled to a one-way clutch 200,
shown in FIGS. 4-5. Assembly to the one-way clutch 200 can cause
the pins 120 to depress into their respective pockets in the
housing 102 while maintaining an adjacent location relative to the
separator spring 110. The pins 120 continue to restrain radial
movement of the separator spring 110 during assembly.
[0030] The one-way clutch 200 is shown in FIGS. 4-5 to have an end
plate 202 that faces the friction plate 108 when assembled. The end
plate 202 may be provided with a plurality of pockets or
depressions 204 formed therein. The depressions 204 are aligned
with the pins 120 when the one-way clutch 200 is properly aligned
and positioned with respect to the clutch 100. The depressions are
indents into the end plate 202 to provide a contact region for the
pins 120. When the clutch 100 and the one-way clutch 200 are
assembled, the pins 120 can therefore extend into both the housing
102 and the end plate 202. This assures the pins 120 can continue
to restrain radial movement of the separator spring 110 regardless
of the gap between the end plate 102 and the friction plate 108
during operation.
[0031] While exemplary embodiments are described above, it is not
intended that these embodiments describe all possible forms
encompassed by the claims. The words used in the specification are
words of description rather than limitation, and it is understood
that various changes can be made without departing from the spirit
and scope of the disclosure. As previously described, the features
of various embodiments can be combined to form further embodiments
of the invention that may not be explicitly described or
illustrated. While various embodiments could have been described as
providing advantages or being preferred over other embodiments or
prior art implementations with respect to one or more desired
characteristics, those of ordinary skill in the art recognize that
one or more features or characteristics can be compromised to
achieve desired overall system attributes, which depend on the
specific application and implementation. These attributes can
include, but are not limited to cost, strength, durability, life
cycle cost, marketability, appearance, packaging, size,
serviceability, weight, manufacturability, ease of assembly, etc.
As such, to the extent any embodiments are described as less
desirable than other embodiments or prior art implementations with
respect to one or more characteristics, these embodiments are not
outside the scope of the disclosure and can be desirable for
particular applications.
* * * * *